MOUSSON’S RECONGELATION APPARATUS

School Spano

Function
Showing the possibility of melting the ice at temperatures inferior to zero centigrade.

Maker: Officine Galileo - Florence

Price: L 170

Purchase date: 1931

Description
It is composed of a solid cylinder of iron with the bottom adjustable with a screw,
of a pressure screw with a waterproof piston and a sphere of steel.
By introducing little bits of ice and pressing them with the screw we obtain a
homogeneous
cylinder of ice. If we put the sphere between the ice and the piston and we keep
the temperature low, the intervention of the pressure provokes the fall of the sphere to the
bottom of the cylinder.

CALEFACTION APPARATUS (Leidenfrost's Drops)

School Spano

Function
Showing the behaviour of water drops on a red-hot surface.

Maker: Officine Galileo - Florence

Price: L 110

Purchase date: 1931

Description
The apparatus is formed by a thick 50 mm diameter capsule of copper with a support
of iron with variable height. For the experiment the capsule must be polished with emery
paper.
When the capsule is red hot, we drop water from a pipette, holding the flame under
the capsule. When the number of drops is enough to form a 20 mm diameter drop, we take off
the flame and can observe the phenomenon of calefaction, which finishes with the evaporation
of the drop, as soon as the temperature of the capsule falls under a certain limit.

APPARATUS FOR MEASURING THE MAXIMUM VAPOUR PRESSURE OF VARIOUS LIQUIDS AT A GIVEN TEMPERATURE

School Spano

Function
Studying the vapour tension of various liquids.

Maker: Officine Galileo - Florence

Price: L 560

Purchase date: 1931

Description
Four barometer tubes are held vertically over a little celluloid tank.
The first tube is a common tube for barometer and it is used for comparison; the other
three have a bulging top which communicates with a small funnel. But the communication is
closed with a stopcock that is used to transfer a drop of liquid from the funnel to the bulb
underneath.
After lubricating the first two stopcocks with fat, and the third one with glycerine,
we prepare the four tubes as in the experiment of Torricelli.
Then we introduce water in the first funnel, in the second we introduce alcohol e in
the third ether, and we turn the keys, until we can see, on the meniscus of mercury, the
liquid that has passed into the barometric room.
At that moment we are in the presence of saturated vapour of water, alcohol, ether,
the maximum vapour pressure at room temperature of which is measured by the difference between
the columns of the closed tube and the columns of mercury that result after the introduction
of the liquids.
We find that at the temperature of 20 °C, there is a difference in height of 17 mm for
the water, a difference of 14 mm for the alcohol, a difference of 430 mm for the ether.
When we warm or we cool the tubes, these values increase or decrease.

FRANCKLIN’S BOILER

School Spano

Function
Showing the ebullition of a liquid at low temperature in the vacuum.

Maker: Officine Galileo - Florence

Price: L 15

Purchase date: 1931

Description
A glass container, ending with two small balloons, contains coloured alcohol.
The air has been driven out almost completely with the ebullition of the liquid before
the welding, so that the liquid cannot bear any other pressure than that of its own vapour.
This pressure is very small at ordinary temperature.
If we hold one of the balloons in the hand its heat gives the vapour a pressure that
is enough to drive the liquid to the other side and to produce a strong ebullition.

WOLLASTON'S CRYOPHORUS

School Spano

Function
Studying the evaporation of the water in very rarefied atmosphere.

Maker: Officine Galileo - Florence

Price: L 15

Purchase date: 1931

Description
A curved glass tube with two spherical balloons at the end.
Some water has been introduced into the tube and has been heated until ebullition,
and then the glass has been closed.
If we make the water pass into the balloons of the short branch, and we immerse the
other balloons into the ice, we have a fast and constant distillation from the upper to the
lower sphere.
The water, that evaporates so quickly, gets so cold that it solidifies.
In this experiment it is advisable to put less than half of the liquid in the upper
sphere to prevent the glass from breaking at the moment of solidification. It is also
advisable to shake the apparatus every now and then to avoid the phenomenon of the
supercooling for which the water could freeze abruptly at the first collision and could
break the container.

LESLIE’S APPARATUS

School Spano

Function
Studying the adiabatic evaporation of a liquid. For the freezing of the water under
a bell jar.

Maker: Officine Galileo - Florence

Price: L 50

Purchase date: 1931

Description
On the edge of a small glass tank that must hold sulphuric acid or sticks of caustic
potash or calcium carbide, we put a brass tripod, that carries a saucer with a smoked cork
bottom. On the cork we put a large drop of water that can freeze because of the evaporation
under the bell jar.
$nbsp; During the experiment it is better to make the drop vibrate in order to free it from
the air it can hold.
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GLASS TUBE WITH CARBON DIOXIDE FOR EXPERIEMENTS ON TEMPERATURE.

School Spano

Function
Studying the behaviour of a liquid in a particular condition.

Maker: Officine Galileo - Florence

Price:

Purchase date: 1931

Description
When the tube is introduced into a large tube full of water at 35 °C, held by a
metallic thread opportunely wrapped, the liquid boils and dilates with a coefficient of
expansion seven times greater than that of the gases. In the meantime the meniscus becomes
mobile and oscillating, and dissolves into a blue opalescence ring and then disappears.
At the critical temperature of 30.9 °C the pressure is 72 atm. and the passage from the
liquid phase to the gaseous phase happens without absorption of heat. Every minimal change
of temperature determines great changes of density, and these produce in the fluid mass
appearances similar to those produced by the mixing of non-coloured liquids or by the air
that flows on the surface of a hot body.
The tube contains liquid carbon dioxide for about two thirds of its own volume at
ordinary temperature.

AUGUST’S PSYCHROMETER

Description
(1) Two identical thermometers divided in fifths or tenths of grade are applied to a
support. One of the thermometers is kept dry and the other is continuously humidified by a
thin muslin or cotton wool covering, that falls into a glass underneath.
When it is invested by a current of air generated by a ventilator the adiabatic cooling of
the bulb of the second thermometer is in function of the quantity of evaporated air and of
the hygrometric state of the air of the room at the moment of the experiment.